# Stud bolt with nuts

> Stud bolts with heavy hex nuts: ASTM A193 B7, B8M and L7 studs with A194 2H nuts for flanged joints, and what to state in the request so it can be quoted.

URL: https://jjprojectsok.com/products/steel-structural/stud-bolt  
Español: https://jjprojectsok.com/es/products/steel-structural/stud-bolt  
Updated: 2026-10-16

Fully threaded rod with a heavy hex nut at each end, used to clamp flanged joints.

**In short:** Fully threaded rod with a heavy hex nut at each end, used to clamp flanged joints. JJ Projects sources it to the specification the buyer names. Typical reference, studs: ASTM A193 B7 (alloy steel), B8 and B8M (stainless), A320 L7 (low temperature).

## Specification references

- Studs: ASTM A193 B7 (alloy steel), B8 and B8M (stainless), A320 L7 (low temperature)
- Nuts: ASTM A194 grade 2H (with B7) or grade 8 and 8M (stainless)
- Thread: Unified inch thread per ASME B1.1
- Coating: Plain or coated, as the order specifies

> Typical references only. The governing specification is the one on your purchase order or datasheet.

## Typical uses

- Bolting of flanged joints in piping, valves and equipment
- Pressure vessel and heat exchanger closures
- High-temperature service with B7 studs, low-temperature service with L7
- Corrosive service with stainless B8 and B8M studs

## What to include in a request

A request with these details can be quoted without a round of questions. Send what you have and we will ask for the rest.

1. Diameter and thread, for example 3/4 in UNC; studs of 1 in and larger are commonly 8-thread series (8UN)
2. Overall stud length, measured from end to end
3. Stud grade and matching nut grade, for example A193 B7 with A194 2H, or B8M with grade 8M
4. Quantity of studs and nuts, noting that each stud takes two nuts
5. Coating or plating if required, for example PTFE-based or zinc
6. Documents: material test report and any marking or test requirement
7. The flange size and class, if you want help working out the stud count and length

[Request this item](https://jjprojectsok.com/request-a-quote?item=stud-bolt)

## Questions

### How is the length of a stud bolt measured?

Stud length is the overall length from one end to the other, not counting the nuts. It must be long enough for full thread engagement through both flanges and the gasket, with the nuts fully threaded on.

### What is the difference between B7 and B8M studs?

ASTM A193 B7 is chromium-molybdenum alloy steel with high strength, used for high-temperature and general pressure service. B8M is austenitic stainless steel for corrosive service, with lower strength than B7. The piping specification names which one applies.

### Which nut goes with a B7 stud?

ASTM A194 grade 2H heavy hex nuts are the usual pairing with A193 B7 studs. For stainless studs the nut is a stainless grade such as 8 or 8M. Pairing is defined in the bolting specification of the project.

## Related items

- [Spiral-wound gasket](https://jjprojectsok.com/products/steel-structural/spiral-wound-gasket): Spiral-wound gaskets to ASME B16.20 with 304 or 316L winding and graphite or PTFE filler, for raised-face flanges, with request details needed to quote.
- [Weld neck flange](https://jjprojectsok.com/products/steel-structural/flange-weld-neck): Forged weld neck flanges to ASME B16.5 and B16.47 in A105, A350 LF2 and A182 grades, and what a flange request needs to state to be quoted properly.
- [Slip-on flange](https://jjprojectsok.com/products/steel-structural/flange-slip-on): Forged slip-on flanges to ASME B16.5 in A105 and A182 grades, raised or flat face, and what to state when you request slip-on flanges for a quote.
- [Blind flange](https://jjprojectsok.com/products/steel-structural/flange-blind): Forged blind flanges to ASME B16.5 and B16.47 in A105 and A182 grades, Class 150 to 2500, and what to include in a blind flange request for a quote.

## Guides

- [Stud bolts and gaskets: ASTM A193 and A320](https://jjprojectsok.com/knowledge/stud-bolts-and-gaskets): How to specify flange bolting and gaskets: ASTM A193 B7, B7M, B8, A194 2H and 2HM nuts, A320 L7, coatings and spiral-wound gaskets to ASME B16.20.
- [Flange pressure classes: ASME B16.5 and B16.47](https://jjprojectsok.com/knowledge/flange-pressure-classes): How ASME flange classes 150 to 2500 work: B16.5 vs B16.47, pressure-temperature ratings, facings RF, FF and RTJ, flange types and common materials.
- [Material test reports (MTRs) and EN 10204](https://jjprojectsok.com/knowledge/material-test-reports): What a material test report contains, how EN 10204 types 2.1, 2.2, 3.1 and 3.2 differ, what heat numbers mean, and what to check against the purchase order.

[All steel and structural](https://jjprojectsok.com/products/steel-structural)